diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index 3904d79..bbbeb98 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -1539,7 +1539,11 @@
 				 * crtc virtual pixel clock.
 				 */
 				if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(test_encoder))) {
-					if (ASIC_IS_DCE5(rdev) || rdev->clock.dp_extclk)
+					if (ASIC_IS_DCE5(rdev))
+						return ATOM_DCPLL;
+					else if (ASIC_IS_DCE6(rdev))
+						return ATOM_PPLL0;
+					else if (rdev->clock.dp_extclk)
 						return ATOM_PPLL_INVALID;
 				}
 			}